Device and method for cooling a housing of a gas turbine or a combustion chamber

A device for cooling a housing of a gas turbine or a combustion chamber thereof, comprising:

• a cooling gas supply device with a cooling gas outlet out of which a cooling gas stream flows during operation of the cooling gas supply device, and a cooling gas inlet via which the cooling gas stream flows back to the cooling gas supply device during operation of the cooling gas supply device;
• a cooling gas path which is led through the housing in a circumferential direction thereof and which connects a first housing connection to a second housing connection;
• a switching device for reversing a direction of flow of the cooling gas stream, the switching device being operable between a first switching position in which the switching device connects the cooling gas outlet to the first housing connection and the cooling gas inlet to the second housing connection, and a second switching position in which the switching device connects the cooling gas outlet to the second housing connection and the cooling gas inlet to the first housing connection.